Very likely your understanding of whips is only theoretical and thus very superficial.
Think of riding a bike and imagine that you knew of bikes and that you "sat" on them and "rode" them, but had never actually seen a bike used, much less ridden a bike yourself. If you where this unfamiliar with bikes, the idea that you might want to stand up on the pedals when going up a steep hill, or that you have to lean into a curve, would probably never occur to you, and in your writing you wouldn't know to say more than that a person "sat on his bike and rode it".
Whips are the same. Since ox carts have gone out of fashion, most of us have never seen a whip, and very few have actually handled one. I grew up in the south of Germany where huge bullwhips ("Karbatsche") are traditionally cracked at the expelling-the-winter festivities ("Fasnacht"). Just watching, you will notice the weight of the whip and how you must employ your whole body to swing and crack it.
Here is a video from YouTube: https://www.youtube.com/watch?v=t1oFlDXB0s8
Of course these people don't fight with their whips, but maybe the endless reservoir of videos on the web contains examples of that, too.
For your writing, it would certainly help you to familiarize yourself with what you are writing about. This question is a prime example for the rule to write what you know.
Your best option would be to get a bullwhip and try how it works. Try to spank a lamp post (instead of yourself), or make the whip's end coil around it so you can pull the post towards you (one of the things "whippists" continually do in fiction, although with the necks of their opponents). It will give you an idea of how much more complex and varied its handling actually is than just "bringing the whip cracking down".
Once you have handled a whip, you will no longer have any difficulties describing its use.
If you want to read how other authors describe the use of whips, go to Google Books and search for something like "brought whip cracking down" and variations thereof.